With the development of display technology, the liquid crystal display device has become the most commonly used display device.
The liquid crystal display device mainly comprises a backlight module and a liquid crystal module. The direct type backlight module is a commonly used backlight module, and mainly comprises a reflective sheet and a plurality of point light sources that are arranged on the reflective sheet. The reflective sheet usually has a rectangular shape, and the edges and corners of the reflective sheet are folded, so that the edges and corners thereof can form inclined surfaces with a certain slope or curved surfaces with a certain curvature. In this manner, the edges and corners of the reflective sheet can reflect the light emitted by the point light sources more effectively, and thus the light-exiting efficiency of the backlight module can be improved.
Since each corner of the reflective sheet is located at an intersection point of two edges, the slope (or curvature) of the corners of the reflective sheet is lower than the slope (or curvature) of the edges of the reflective sheet. Consequently, the light reflected by the corners of the reflective sheet is relatively less, and thus dark spots would exist at the corners of the liquid crystal display device.